- 50-round drum magazine
- Fits Ruger P91 .40 S&W pistol
- Magazine body constructed of a proprietary DuPont Zytel based polymer
- Blue steel upper magazine tower
- Injection molded magazine follower
- Magazine spring formed from heat treated stainless steel
- Made in USA
ProMag magazines are designed utilizing both traditional stamping and welding of heat-treated high carbon steel, and modern precision injection molding of mil-spec polymer compounds. Every ProMag magazine is backed by a lifetime guarantee against manufacturer's defects. Made in USA.